000
AXPZ20 KNHC 100320
TWDEP
Tropical Weather Discussion
NWS National Hurricane Center Miami FL
0405 UTC Sat Dec 10 2016
Tropical Weather Discussion for the eastern Pacific Ocean from
the Equator to 32N, east of 140W. The following information is
based on satellite imagery, weather observations, radar, and
meteorological analysis.
Based on 0000 UTC surface analysis and satellite imagery through
0300 UTC.
...SPECIAL FEATURES...
Gulf of Tehuantepec Gale Warning: Scatterometer data at 1630 UTC
showed gale force winds north of 15N in the Gulf of Tehuantepec.
A tight pressure gradient analyzed across the region tonight is
expected to support sustained winds to around 45 kt. Max seas
will build to 17-18 ft by early Saturday. Gale conditions will
persist until Sunday morning, then pulse to 25-30 kt each night
from Sunday night through Tuesday night.
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
The monsoon trough axis extends from 10N84W to 06N91W to 07N97W.
The ITCZ extends from 07N103W to 09N116W to 07N128W to 08N140W.
Scattered moderate convection is from 08N to 12N between 111W
and 122W.
...DISCUSSION...
OFFSHORE WATERS WITHIN 250 NM OF MEXICO...
Gulf of California: A weakening pressure gradient between a
surface trough along the Mexico coast and high pressure over the
east Pacific will continue to support fresh northwest winds over
the Gulf of California S of 27N tonight. High pressure northwest
of the area will weaken by late Saturday, allowing gentle to
moderate winds to prevail through mid-week.
Ridging dominates elsewhere in offshore waters of Mexico with a
high centered near 29N125W. Aside from the Tehuantepec high wind
event, light to gentle winds will prevail S of 17N through the
forecast period. Fresh to occasionally strong northwest winds
west of Baja California will continue through Sunday night, then
become moderate to fresh as the ridge weakens slightly. From 17N
north to Mazatlan moderate to fresh northwest winds will prevail.
OFFSHORE WATERS WITHIN 250 NM OF CENTRAL AMERICA, COLOMBIA, AND
WITHIN 750 NM OF ECUADOR...
Gulf of Papagayo: Fresh to strong offshore winds east of 90W will
continue to pulse mainly during the overnight hours this weekend.
Max seas will be around 8 ft during the event. An easterly wave
in the central Caribbean will cross Central America Monday. Some
model guidance indicates low pressure development along the wave
axis as it moves west of the coast Tuesday through Wednesday.
But lacking consensus between models, favor keeping it a strong
trough or weak low in forecast grids.
Light to gentle north to northeast winds and combined seas of 3
to 5 ft are occurring north of the monsoon trough, which is
expected to meander between 08N and 10N through Wednesday. Light
to moderate southwest flow is observed from 05N to 09N, with
combined seas of 3 to 5 ft in southwest swell. Moderate to fresh
southerly flow is expected south of 05N through Wednesday.
REMAINDER OF THE AREA...
High pressure centered near 29N126W extends with a ridge axis
southeast to near 21N110W. Gentle to moderate north-northwest
flow is expected northeast of the ridge axis this weekend and
moderate to fresh trades will prevail south of the ridge axis,
north of the ITCZ. Fresh to occasionally strong NE winds and
combined seas of 8 to 9 ft will generally prevail from 07N to
15N W of 120W through Sunday. Low pressure approaching the far
northwest waters will weaken the ridge on Tuesday and Wednesday,
allowing winds and seas in this area to subside.
$$
Mundell